B-cell lymphoma-extra large messenger RNA (Bcl-xL mRNA) (Bcl-xL mRNA)

B-cell lymphoma-extra large (Bcl-xL) messenger RNA (mRNA) is the primary transcript of the BCL2L1 gene and serves as a critical regulator of the intrinsic apoptotic pathway. The Bcl-xL protein translated from this mRNA is a potent anti-apoptotic member of the Bcl-2 family that maintains mitochondrial integrity by sequestering pro-apoptotic proteins like BAK and BAX (UniProt, 2023). Overexpression of Bcl-xL mRNA is a hallmark of various malignancies, including lung, breast, and prostate cancers, where it contributes to tumor cell survival and resistance to chemotherapy (Zhang et al., 2020). A unique feature of this target is its alternative splicing; the BCL2L1 pre-mRNA can be processed into the anti-apoptotic Bcl-xL or the pro-apoptotic Bcl-xS isoform (Boise et al., 1993). Therapeutic interventions targeting the mRNA include antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) designed to reduce Bcl-xL expression, as well as splice-switching oligonucleotides (SSOs) that redirect splicing to favor the Bcl-xS variant (Mercatante et al., 2001). However, a major clinical hurdle is the essential role of Bcl-xL in maintaining the lifespan of mature platelets, meaning that systemic inhibition of Bcl-xL mRNA often leads to dose-limiting thrombocytopenia (Mason et al., 2007).

Other names

BCL2L1 mRNAB-cell lymphoma 2-like 1 mRNABcl-2-like protein 1 mRNABcl-x mRNABCL2L1 transcript variant 1

Antisense-mediated RNase H degradation of mRNA, RNA interference (RNAi) via the RISC complex, and splice-switching to redirect pre-mRNA processing from Bcl-xL to the pro-apoptotic Bcl-xS isoform.